1)Pressure cooker:Aluminium or S/S body &cover,polished surface 2)Quick& heat transmission ... ,high quality pressure cooker3) The silicon sealing ring, without poison or odor, sealing well, easy to open and close the lid4 ... ) Quick and even heat transmission pressure cooker6) Pressure cooker: all size 3L,4L,5L,7L,9L,11L,13L ,15L ,18L,20L ...